PROJECT ABSTRACT For the millions of Americans who experience the possible physical, psychological, and social effects of severe and chronic illness, palliative care can be essential to supporting an optimal quality of life. Estimates suggest that two-thirds of all people in the US could benefit from palliative care at some point, and this estimate does not include the family members and caregivers who may also benefit. The delivery of high-quality, patient- centered palliative care depends upon end-of-life and palliative care (EOLPC) Research. Realizing the full benefits of palliative care research requires the engagement of patients, families, and caregivers in every phase of research. Effective engagement can make research better by increasing the relevance of research questions to patients, enhancing recruitment, and improving dissemination & implementation of research results. However, engagement can raise ethical challenges - such as ensuring engagement participants are truly representative of the broader patient population and that engagement does not present undue burdens ? that have only recently been explored, but not in EOLPC Research. Because EOLPC Research is a unique setting, it can present unique ethical challenges to effective engagement. Patients may be vulnerable due to their state of illness (such as in the frail elderly) or due to absent or intermittent decision-making capacity. Family caregivers may struggle to know and represent patients' priorities or have difficulty engaging due to ongoing grief. Any potential ethical challenges may be particularly relevant for individuals who are doubly vulnerable because of existing racial, ethnic, socioeconomic, and geographic disparities in access to EOLPC. Explicitly eliciting their preferences about research is critical for shaping research that meets their needs. The goals of this project are to advance the science of bioethics and engagement in research and to provide ethics guidance to support researchers in engaging palliative care patients, caregivers, and others in EOLPC Research. We will achieve this goal by (1) using semi-structured interviews to obtain insights into the real- world ethical challenges facing investigators as well as patients, family members, and caregivers in EOLPC research engagement; (2) defining outcomes of importance to the different stakeholders; and (3) creating practical ethics guidance for identifying and managing ethical issues in engaging patients in EOLPC research. The project will be conducted within the Palliative Care Research Cooperative Group (PCRC) (U2C NR014637), a robust interdisciplinary research community comprised of more than 500 members at more than 180 sites. This supplement will build on the existing resources of the PCRC to enhance the patient-centered palliative care research and address gaps in the evidence base related to patient engagement in EOLPC Research.